🎙️ Audio Broadcaster

A real-time audio broadcasting application with live speech-to-text transcription and translation capabilities. Built with Electron, Node.js, and Python.

Features

• Real-time Audio Broadcasting: Stream audio to multiple listeners using WebRTC
• Speech-to-Text Transcription: Automatic transcription of spoken audio using Google Speech Recognition (free)
• Live Translation: Translate transcribed text to multiple languages using MyMemory Translation API (free)
• Multi-platform Support: Works on macOS, Windows, and Linux
• Low Latency: Optimized for minimal delay in audio transmission
• Modern UI: Clean, responsive interface for both broadcasters and listeners
• 100% Free: No API keys or paid services required

Architecture

• Frontend: HTML5, JavaScript, WebRTC
• Backend: Node.js with Express and Socket.IO
• Desktop App: Electron framework
• Transcription Engine:
  • Online Mode: Google's free Web Speech API (requires internet)
  • Offline Mode: Vosk (fully open source, no internet required)
• Translation: MyMemory Translation API (free, 1000 words/day anonymous)

Prerequisites

Before running this application, ensure you have:

• Node.js (v16 or higher)
• Python (v3.8 or higher)
• npm or yarn
• Microphone access on your device
• Internet connection (for translation features)

Installation

1. Clone the repository

git clone https://github.com/yourusername/audio-broadcaster.git
cd audio-broadcaster

2. Install Node.js dependencies

npm install

3. Set up Python environment

# Create a virtual environment
python3 -m venv venv

# Activate the virtual environment
# On macOS/Linux:
source venv/bin/activate
# On Windows:
venv\Scripts\activate

# Install Python dependencies
pip install -r requirements.txt

4. Translation Setup (Automatic)

Translation uses MyMemory Translation API by default. No configuration or API key needed!

Free tier limits:

• Anonymous usage: 1000 words per day
• With email registration: 10,000 words per day

The free tier is more than sufficient for most church and small organization use cases.

5. Offline Mode Setup (Optional - for churches without internet)

By default, the app uses Google's free Web Speech API (requires internet). For offline operation:

Step 1: Download a Vosk model

# Download a small English model (39 MB, good accuracy)
curl -O https://alphacephei.com/vosk/models/vosk-model-small-en-us-0.15.zip
unzip vosk-model-small-en-us-0.15.zip
mv vosk-model-small-en-us-0.15 vosk-model

# Or download other models from: https://alphacephei.com/vosk/models
# Larger models offer better accuracy but require more resources

Step 2: Enable offline mode

Edit transcribe.py and change line 15:

TRANSCRIPTION_MODE = 'offline'  # Change from 'online' to 'offline'

Step 3: Restart the app

npm start

The app will now work completely offline! Perfect for churches in areas with poor/no internet connectivity.

Usage

Start the Application

npm start

This will:

1. Launch the Electron app
2. Start the Express server
3. Initialize the Python transcription service

Broadcaster Interface

The broadcaster window will open automatically. You can:

• Start/stop broadcasting audio
• Enable/disable transcription
• Toggle translation
• Select target language for translation
• View connection information to share with listeners

Listener Interface

Listeners can connect by opening their browser to:

http://[BROADCASTER_IP]:[PORT]/listen_v2.html

The broadcaster will display the connection URL in their interface.

Configuration

Audio Device Selection

The application will attempt to use your default microphone. You can modify the device selection in transcribe.py if needed.

Supported Languages

The translation feature supports all languages available in Google Cloud Translation API. Common language codes:

• es - Spanish
• fr - French
• de - German
• ja - Japanese
• zh - Chinese
• And many more...

Building for Production

To create distributable packages:

npm run build

This will create platform-specific packages in the dist/ directory.

Project Structure

audio-broadcaster/
├── main.js              # Electron main process
├── preload.js           # Electron preload script
├── transcribe.py        # Python transcription service
├── package.json         # Node.js dependencies
├── requirements.txt     # Python dependencies
└── public/
    ├── broadcaster.html # Broadcaster interface
    ├── listen_v2.html   # Listener interface
    └── test.mp3         # Test audio file

Troubleshooting

Microphone Not Working

• macOS: Grant microphone permissions in System Preferences > Security & Privacy > Microphone
• Windows: Check microphone settings in Windows Settings > Privacy > Microphone
• Linux: Ensure your user has access to audio devices

Python Process Fails

• Verify Python virtual environment is activated
• Check that all dependencies are installed: pip install -r requirements.txt
• Ensure PyAudio is properly installed (may require system audio libraries)

Translation Not Working

• Ensure you have an active internet connection
• Check the console logs for any MyMemory API errors
• Verify the target language code is correct (e.g., 'es' for Spanish, 'fr' for French)
• If you exceed the daily limit (1000 words), translation will stop working until the next day

Port Already in Use

The application will automatically select an available port. If you need a specific port, set the PORT environment variable:

PORT=3000 npm start

Known Limitations

• Online mode requires an active internet connection for transcription and translation
• Offline mode (Vosk) works without internet but:
  • Only transcription works offline (translation still requires internet)
  • Requires downloading a language model (39+ MB)
  • Small models (vosk-model-small-en-us-0.15) are very sensitive to background noise and may transcribe words when no one is speaking
  • For production use, consider larger models (vosk-model-en-us-0.22, 1.8 GB) which have better silence detection
  • Offline mode is experimental and best tested in quiet, controlled environments
  • Slightly less accurate than Google's online API overall
• Transcription default language is English (can be changed by using different Vosk models)
• Translation requires internet (MyMemory API has daily limit of 1000 words for anonymous usage)
• WebRTC connections may require network configuration for remote access

📄 License

This project is licensed under a Non-Commercial License with Donation Button Requirement.

Key Points:

• ✅ Free to use for churches and non-profit organizations
• ✅ Can modify and adapt for your needs
• ✅ Must keep ChurchApps.org donation button visible
• ❌ Cannot sell or use commercially
• ❌ Cannot remove donation button

See LICENSE file for full details.

For commercial licensing inquiries, contact: micheal@livechurchsolutions.org

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

Development Guidelines

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Test your changes thoroughly
4. Commit your changes (git commit -m 'Add some AmazingFeature')
5. Push to the branch (git push origin feature/AmazingFeature)
6. Open a Pull Request

💡 Support & Questions

• Issues: GitHub Issues
• Email: micheal@livechurchsolutions.org
• ChurchApps: churchapps.org

🙏 Acknowledgments

• Built with ❤️ for churches and non-profit organizations
• MyMemory Translation API for free translation services
• Google Speech Recognition (free tier)
• The Electron, Node.js, and Python communities
• WebRTC for real-time communication
• Thanks to all contributors and organizations using this system

📈 Roadmap

• Multi-language UI support
• Recording and playback features
• Advanced audio mixing controls
• Mobile app for iOS/Android
• Cloud-based audio relay for larger audiences
• Integration with streaming platforms

---

Made with ❤️ for churches and ministry